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2 messages · Doran, Harold, Remko Duursma

Doran, Harold
# 
I've built a package that contains only two functions for a test run. They are:

g <- function(x){
	x <- x^2
	class(x) <- "foo"
	x
}

print.foo <- function(x, ...){
	cat("This is a test:\n")
	cat(x, "\n")
	invisible(x)
	}

Simply testing these functions in the R workspace prior to a build yields:
This is a test:
1 4 9 16 25 

Now, I includes a NAMESPACE for this package, and it includes only the following:

export(g)

Package build is now succesful. However, here is what occurs:
[1]  1  4  9 16 25
attr(,"class")
[1] "foo"

Why is the attribute printed on screen here whereas this does not occur when the function print.foo is simply sourced into the R workspace?

Thanks,
Harold
R version 2.10.0 (2009-10-26) 
i386-pc-mingw32 

locale:
[1] LC_COLLATE=English_United States.1252 
[2] LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] foo_1.0
Remko Duursma
# 
Because print.foo is not defined if you only include the function "g"
in your namespace.



remko


-------------------------------------------------
Remko Duursma
Post-Doctoral Fellow

Centre for Plants and the Environment
University of Western Sydney
Hawkesbury Campus
Richmond NSW 2753

Dept of Biological Science
Macquarie University
North Ryde NSW 2109
Australia

Mobile: +61 (0)422 096908
www.remkoduursma.com
On Tue, Nov 10, 2009 at 8:14 AM, Doran, Harold <HDoran at air.org> wrote: